摘要:Dysbiosis is a condition that can cause various clinical disorders, from gastrointestinal problems to allergies or even cancer. Resetting the microbiota using antibiotics and/or probiotics could be a possible therapy for many diseases. The aim of this study was to evaluate the effects of three treatment regimens in patients with irritable bowel syndrome (IBS). The regimens were short-term rifaximin treatment (10 days) followed by either a nutraceutical agent (G1) or a low- Fermentable, Oligo-, Di-, Monosaccharide and Polyol (FODMAP) diet (24 days) (G3) or treatment with MegaSporeBiotic a mixture of spores of five Bacillus spp. for medium-term (34 days) (G2). Ninety patients with IBS without constipation were enrolled and divided into three groups (G1, G2, G3). Patients in G1 and G3 were evaluated over four visits (baseline/first day (V1), 10 days (V2), 34 days (V3), 60 days (V4)), and, those in G2 over three visits (V1, V3, V4). Severity score, quality of life, and parameters from the rectal volume sensation test were determined. The results demonstrated that patients treated with MegaSporeBiotic, compared with those treated with rifaximin followed by nutraceutical or low-FODMAP diet, had similar severity scores and rectal volume sensation test results for all parameters tested and statistically significant improvement in measurements of quality of life.